Try and handle conflict on update: it's a plan

[bendem]

This is a plan to fix the data loss part of #395. I know absolutely nothing of the codebase and my years of php are far. I already have a functional PoC, but that's not the best user experience and I'm afraid getting it polished is beyond what I'm able to do for now.

Video of it in action:

demo.bookstack.conflict.mp4

[ssddanbrown]

Thanks for the suggestion and PR @bendem.

I'm not opposed to introducing a higher barrier to saving overlapping changes, but I wouldn't want to outright prevent it like in this implementation, I don't want to be leading users into hard blocks/dead-ends.

We could do something similar to this but:

• On save compare created dates between actual page latest revision and user draft (if existing).
• If user draft less created before page latest revision,
  • Save submitted content to user draft.
  • Return to editor with warning about potential conflicts.
  • Require secondary confirmation (save again after being shown warning) before actual save.

[bendem]

Agreed, this was mostly to illustrate my comment. I'm not in a position to push this further, but I hope it can spark a contribution from someone more familiar with php and the codebase.